I. Field of the Invention
This invention relates to a gas-sealing insert for floor drains, and particularly for floor drains located in the basements of buildings.
II. Description of the Prior Art
It has recently become known that many houses and other buildings are built on soil and/or rock that slowly exudes radon gas, which is a radioactive gas which can cause cancer and other health problems. Over a period of time, the radon can accumulate in the building until harmful levels are reached. The currently popular trend of sealing buildings to make them more air-tight in order to reduce energy losses increases the danger of excessive radon build-up.
Many houses and other buildings have a concrete slab forming the basement floor and this acts as a barrier to the seepage of radon gas. However, it is usual to provide a drain in the basement floor and the floor drain may permit the entry of radon gas into the basement, particularly when the water in the U-trap usually provided in such drains dries out. This is a common occurrence because such floor drains are rarely used for the removal of water from the basement, so the water in the U-trap is rarely replenished.